1. Field of the Invention
The present invention relates to a substrate structure and a method of manufacturing the same, and more particularly, to a substrate structure capable of preventing corrosion and discoloration of a conductive pattern used as circuit wiring and improving soldering and wire bonding characteristics, and a method of manufacturing the same.
2. Description of the Related Art
In general, a substrate such as a printed circuit board is widely used for packaging of electronic components such as semiconductor integrated circuit (IC) chips. In this substrate, a fine circuit pattern is formed on an insulating substrate. A soldering process is performed on a portion of the circuit board for mounting of the electronic components, and a wire bonding process is performed on another portion of the circuit pattern for electrical connection with the electronic components.
However, since the circuit pattern containing copper is easily corroded, it acts as a factor that deteriorates the soldering and wire bonding characteristics. In order to prevent this, various kinds of plating processes are performed on the copper circuit pattern. There are a silver plating process and a gold plating process that are used as plating processes for preventing corrosion of the copper circuit pattern.
However, since a conventional silver plating process applies an immersion silver plating method, it causes discoloration such as yellowing or blackening through reaction with sulfurous acid gas or chlorine gas in the atmosphere. In this case, soldering characteristics are deteriorated and a short of a circuit pattern occurs due to continuous corrosion of the circuit pattern. Further, since a conventional gold plating process uses a great quantity of relatively expensive gold, there is a problem that manufacturing costs of a circuit board is greatly increased.